1. Field of the Invention
The present invention relates to techniques of design security for integrated circuits (IC), especially the secure synthesis. Specifically, the present invention relates to the protection of the intellectual property (IP) of the IC designs from third party foundries via a “free” encryption.
2. Related Art
With higher mask costs and increasing minimum lot sizes—the two economical trends of the semiconductor industry—most IC design companies are fabless companies, and their designs must be manufactured by third party foundries. Outsourcing manufacturing to low-cost providers overseas will save millions of dollars per chip-design. However, unscrupulous manufacturers with access to ASIC mask sets may “overbuild” chips and sell the excess to the black market, with implications reaching as high as national security. Even the design cycle could now be outsourced to third parties. For instance, a company could outsource the physical synthesis to a third party. For some extremely sensitive designs, it is necessary to limit the number of people who has access to the real functional designs, even within the same IC design company.
The best so far solution to address this manufacture outsourcing issue is adding a manufacturing security system with sophisticated hardware blocks to a customer's chip design at every level of the production cycle, referencing [1]. Thus, only chips that have been through the correct production cycle will work, and the fabless design companies can protect their IP during the manufacture.
However, the technology in [1] has to add extra hardware, like decryptors, onto the chip, which will not only make the formal verification impossible and the simulation complex, but will also increase the chip area and reduce the chip performance. Furthermore, solution in [1] does not address the issue of protecting the IP during the design stage.